Vega VEGASON 61 Operating Instructions Manual page 18

4 Mounting
Standpipe measurement
Flow measurement with
rectangular overfall
18
By using a standpipe (surge or bypass tube), the influence of vessel
installations, foam generation and turbulence is excluded.
Standpipes must extend all the way down to the requested min. level,
as measurement is only possible within the tube.
Fig. 14: Standpipe in the tank
1 Vent hole: ø 5 ... 10 mm (0.197 ... 0.394 in)
VEGASON 61 can be used from tube diameters of 40 mm (1.575 in).
Avoid large gaps and thick welding joints when connecting the tubes.
Generally carry out a false signal suppression.
Measurement in a standpipe is not recommended for extremely
adhesive products.
The short examples give you introductory information on flow
measurement. Detailed planning information is available from flume
manufacturers and in special literature.
3 ... 4 h
max
90°
2
2
Fig. 15: Flow measurement with rectangular overfall: d
the sensor (see chapter " Technical data"); h
spillway
1 Overfall orifice (side view)
2 Upstream water
3 Tailwater
4 Overfall orifice (view from tailwater)
max.
1
min.
1
≥ 50 mm
3
3
= max. filling of the rectangular
max.
VEGASON 61 • Four-wire 4 ... 20 mA/HART
90°
4
= blocking distance of
min.